What is the maximum equivalent length of a boiler’s flue?

October 24th 2023

The maximum horizontal equivalent flue lengths (after the first elbow) is: 20m

The maximum vertical equivalent flue lengths is: 21m

Allow 1.3 meters of flue length for each 87° bend

1.0 meters of flue length for each 45° bend.

 

Maximum horizontal equivalent flue lengths (m)Maximum vertical equivalent flue lengths (m)87° Elbow (m)45° Elbow (m)
NCB-CE20211.31.0
NCB300781.31.0
NCB500781.31.0
NCB70020211.31.0
LCB70020211.31.0
NPE A/S20212.41.2

 

Note: The maximum horizontal equivalent flue length is measured after the first elbow.

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